Langerhans cells in lichen planus and lichenoid mucositis an immunohistochemical study.

Aim: The aim of this study is to identify and evaluate Langerhans cell (LC) in lichen planus (LP), lichenoid mucositis (LM) and normal mucosa (NM) using CD1a monoclonal antibody immunohistochemically. Materials and Methods: A total of 15 cases of oral lichen planus and 15 cases of LM were selected based on clinical examination and confirmed by histopathological analysis. The biopsies from the 10 patients were taken from normal buccal mucosa as control. Paraffin blocks of tissue were made, which are used for routine hematoxylin and eosin staining and immunohistochemical staining using biotin streptavidin methods (CD1a monoclonal antibody). Analysis of CD1a expression was performed by evaluating the labeling index (LI) for each slide. Results: The mean CD1a LI for LP was significantly higher than that of LM and NM in the basal and supra basal layer. The mean CD1a positive cells in the connective tissues for LP were higher than that of LM and NM. Conclusion: This study clearly demonstrates a statistically significant increase in number of LC in LP than in LM, indicating the possible different immunopathogenic mechanisms. [ABSTRACT FROM AUTHOR]